The name of the 21st class is a compound of two Greek words, CRYPTO and GAMIA, signifying a concealed union.

Natural Families. {21. CRYPTO-GAMIA,

Lichens.

Mushrooms.

Ferns.

Mosses.

The number of classes as arranged by Linnæus, was twenty-four. Two of them, Poly-adelphia, (many brotherhoods,) which was the eighteenth class; and Poly-gamia, (many unions,) the twenty-third class, are now, by many botanists,* rejected as unnecessary. The eleventh class, Dodecandria, which included plants whose flowers contain from twelve to twenty stamens, has been more recently omitted. The plants which were included in these three classes have been distributed among the other classes.

The Orders of Linnæus.

The orders of the first twelve classes are founded upon the number of PISTILS.

The orders are named by prefixing Greek numerals to the word GYNIA, signifying pistil.

ORDERS.

Names.
1. MONO-GYNIA,

2. DI-GYNIA,

No. of pistils.

1.

2.

3.

13. POLY-GYNIA, over ten pistils.

The classes vary as to the number of orders which they contain. The orders of the 13th class, Didynamia, are but two.

1. GYMNOSPERMIA. From GYMNOS, signifying naked, and SPERMIA, Sends usually four, lying in signifying seed, implying that the seeds are not covered by a seed vessel.

the calyx.

2. ANGIOSPERMIA. Seeds numerous in a capsule.

From ANGIO, signifying bag or sack, added to
SPERMIA, implying that the seeds are covered.

* A few writers still retain the 24 classes of Linnæus ;-but in the works of Eaton, Torrey, Beck, and Nuttall, only 21 are adopted.

What does Cryptogamia signify ?--Classes omitted-Orders of the first twelve classes, on what founded -How are the orders named ?-Orders of the class Didy namia.

The orders of the 14th class, Tetradynamia, are two, both distin guished by the form of the fruit.

1. SILICULOSA. Fruit, a silicula, or roundish pod. 2. SILIQUOSA. Fruit, a siliqua, or long pod.

The orders of the 15th class, Monadelphia, and of the 16th class, Diadelphia, are founded on the number of stamens, that is, on the characters of the first twelve classes, and they have the same names, as Monandria, &c.

The 17th class, Syngenesia, has its five orders distinguished by different circumstances of the florets, as:

1. EQUALIS. Stamens and pistils equal, or in proportion; that is, each floret has a stamen, a pistil, and one seed. Such florets are called perfect.

2. SUPERFLUA. Florets of the disk perfect, of the ray containing only pistils, which without stamens are superfluous.

3. FRUSTRANEA. Florets of the disk perfect, of the ray neutral, or without the stamen or pistil; therefore frustrated, or useless.

4. NECESSARIA. Florets of the disk staminate, of the ray pistillate ; the latter being necessary to the perfection of the fruit.

5. SEGREGATA. Florets separated from each other by partial calyxes, or each floret having a perianth.

The orders of the 18th class, Gynandria, of the 19th class, Monocia, and the 20th class, Diœcia, like those of the 15th and 16th classes, depend on the number of stamens.

The orders of the 21st class, Cryptogamia, constitute six natural families.

1. FILICES,-includes all Ferns, having the fruit on the leaves. 2. MUSCI,-Mosses.

3. HEPATICAE,-Liverworts, or succulent mosses.

4. ALGAE,-Sea-weeds, and frog spittle.

5. LICHENES, Lichens, found growing on the bark of old trees, old wood, &c.

6. FUNGI,-Mushrooms, mould, blight, &c.

Note.-No confusion is produced in taking the character of some classes, for orders in other classes; for example: if you have a flower with ten stamens, united by their filaments into one set, you know by the definition of the classes that it belongs to the class Monadelphia; you can then, because it has ten stamens, place it in the order Decandria.

LECTURE V.

METHOD OF ANALYZING PLANTS BY A SERIES OF COMPARISONS-GENERAL REMARKS UPON PLANTS-METHOD OF PRESERVING PLANTS FOR AN HERBARIUM -POISONOUS plants, and THOSE WHICH are not poisONOUS.

THE dissection of a plant is, properly, analysis; the meaning of the term being a separation: but when we speak of analyzing plants, we mean something more than examining each part of the flower; this is, indeed, the first step in the process; but by analysis, we learn the Class, Order, Genus, and Species of the plant. A person engaged in ascertaining the name of a plant, may be said to be upon a Botan

Of Tetradynamia-Of the classes Monadelphia and Diadelphia-Of the class Syngenesia-Of the classes Gynandria, Monccia, and Diccia-Of the class Cryptogamia-Meaning of the word analysis-How used in Botany

ical Journey, and the plant being his Directory; if he can read the botanical characters impressed on it by the hand of Nature, he will, by following system, soon arrive at his journey's end.*

Let us suppose, then, we have before us a plant in blossom, of whose name and properties we are ignorant.-The name must be first ascertained, and this can only be done with certainty by the Linnæan system.

In the first place we have two comparisons to make.

1st. Whether the Stamens and Pistils are VISIBLE.

2d. Whether they are INVISIBLE.

If the Stamens and Pistils are not visible, we have already arrived at the class, which is CRYPTOGAMIA.

If, however, the Stamens and Pistils are visible, we have now two comparisons to make.

1st. Whether the flowers have stamens and pistils on the same corolla.

2d. Whether the Stamens and Pistils are placed on different co

rollas.

If the Stamens and Pistils are on different flowers, we then shall find our plant either in the class Diæcia or Monacia; according as the Stamens and Pistils are on different flowers, proceeding from the same root, or from different roots.

But if our plant has the Stamens and Pistils both enclosed in the same corolla, we must next examine,

1st. Whether the Anthers are separate, or,

2d. Whether the Anthers are united.

If we find five anthers united around the pistil, we have found the class of our plant; it is SYNGENESIA.

If the Anthers are separate, we must proceed to a fourth stage, and see,

1st. Whether the filaments are separate, or,

2d. Whether the filaments are united with each other, or,

3d. Whether the filaments are united to the pistil.

If the latter circumstance is ascertained, we need search no farther; our plant is in the class GYNANDRIA.

If the flower has not the filaments united to the pistil, we must ascertain if the filaments are united with each other if they are so, and in two parcels or sets, the flower is in the class DIADELPHIA, but, If in one parcel or set, it is in the class MONADELPHIA.

But if the filaments are separate, we must next examine,

1st. Whether these are similar in length, or,

2d. Whether they are of different lengths.

(Of different lengths, those only which have four or six stamens are to be regarded.)

If we find our flower has six stamens, four long and two short, we need go no farther, this is the class TETRADYNAMIA.

If the flower has four stamens, two long, and two short, it is in the class DYDYNAMIA.

If our flower comes under none of the foregoing heads, we must then count the number of stamens; if these amount to more than ten, we must then consider their insertion, as,

* Thornton.

What two comparisons to be first made in analyzing a plant-When the stamens and pistils are enclosed in the same corolla, what is next to be considered ?-When the anthers are separate, what must be done?-If the filaments are separate, what must be observed ?-If the flower has not stamens of unequal length, what is to be observed ?

1st. Whether inserted on the calyx or corolla, 01, 2d. Whether inserted on the Receptacle.

If we find the Stamens inserted on the Receptacle, the flower is in the class POLYANDRIA; but if on the Calyx or Corolla, it is in ICOSAN

DRIA.

If our flower has less than twenty stamens, with none of the pecuiarities above mentioned, of connexion, position, or length, we have only to count the number of stamens, in order to be certain of the class; if there are ten stamens, it is in DECANDRIA; and so on through the nine remaining classes. This is the true analytical process; but when we put plants together to form a species, and species together to form a genus, and genera together to form an order, and orders together to form a class, we then proceed by Synthesis, which means putting together.

General Facts relating to Vegetables.

Plants are furnished with pores, by which they imbibe nourishment from surrounding bodies. The part which fixes the plant in the earth, and absorbs from it the juices necessary to vegetation, is the root; this organ is never wanting.

The stem proceeds from the root; sometimes it creeps upon the earth, or remains concealed in its bosom; but generally, the stem ascends either by its own strength, or, as in the case of vines, by supporting itself upon some other body. The divisions of the stem are its branches; the divisions of the branches are its boughs. When the vegetable has no stem, the flower and fruit grow from the tops of the root; but when the stem exists, that or its branches bear the leaves, flowers, and fruits. Herbs have generally soft, watery stems, of short duration, which bear flowers once, and then die.

Trees and shrubs have solid and woody stems; they live and bear flowers many years.

Small bodies of a round or conical form, consisting of thin scales, lying closely compacted together, appear every year upon thẻ stems, the boughs, and the branches of trees. They contain the germs of the productions of the following years, and secure them from the severity of the seasons. These germs, and the scales which cover them, are called buds. The buds of the trees and shrubs of equinoctial countries, have few scales, as they are less needed for protection against inclemencies of weather.

Leaves, like flowers, proceed from buds; the former are the lungs of vegetables; they absorb water and carbonic acid from the atmosphere, decompose them by the action of rays of light, and exhale or give out oxygen gas.

Vegetables, like animals, produce others of their kind, and thus perpetuate the works of creation. The organs essential to the perfection of plants, are the stamens and pistils. Those plants in which the stamens and pistils are manifest, are called Phenogamous; where these are rather suspected than demonstrated to exist, they are called Cryptogamous. The presence of a stamen and pistil only constitutes a perfect flower; but in general, these organs are surrounded with an inner envelope, called the corolla, and an outer one, called the calyx. When there is but one envelope, as in the tulip, this is often called by the more general term of perianth, which signifies, surrounding the flower. Persons ignorant of botany, give exclusively

When is the flower in one of the first ten classes ?-Difference between analysis and Bynthesis-Stem-Branches-Boughs-Herbs-Trees and Shrubs-Buds-LeavesPherogamous and Cryptogamous plants.

the name of flower to these envelopes, which are often remarkable for the brilliancy of their colours, the elegance of their forms and the fragrance of their perfumes.

Method of preserving Plants, and of preparing an Herbarium.

Plants collected for analysis, may be preserved fresh many days in a close tin box, by occasionally sprinkling them with water; they may also be preserved by placing their stems in water, but not as well by the latter, as the former method. While attending to the science of Botany, you should keep specimens of all the plants you can procure. An herbarium neatly arranged is beautiful, and may be rendered highly useful, by affording an opportunity to compare many species together, and it likewise serves to fix in the mind the characters of plants. It is a good method in collecting plants for an herbarium, to have a port-folio, or a book in which they may be placed before the parts begin to wilt. Specimens should be placed between the leaves of paper, either newspaper or any other kind which is of a loose texture, and will easily absorb the moisture of the plants; a board with a weight upon it should then be placed upon the paper containing them; the plants should be taken out frequently at first; as often as once or twice a day, and the paper dried, or the plants placed between other dry sheets of paper. Small plants may De dried between the leaves of a book. Plants differ in the length of time required for drying as they are more or less juicy; some dry in a few days, others not sooner than two or three weeks. When the specimens are dry, and a sufficient number collected to commence an herbarium, a book should be procured, composed of blank paper, (white paper gives the plants a more showy appearance.) A quarto size is more convenient than a folio. Upon the first page of each leaf should be fastened one or more of the dried specimens, either with glue or by means of cutting through the paper, and raising up loops under which the stems may be placed. By the sides of the plants should be written the class, order, generic, and specific name; also the place where found, and the season of the year. The colours of plants frequently change in drying; the blue, pale red, and white, often turn black, or lose their colour; yellow, scarlet, violet, and green, are more durable. An herbarium should be carefully guarded against moisture and insects; as a security against the latter, the plants may be brushed over with corrosive-sublimate.

Botanical Excursions.

As a healthful and agreeable exercise, we would recommend frequent botanical excursions; you will experience more pleasure from the science, by seeing the flowers in their own homes; a dry grove of woods, the borders of little streams, the meadows, the pastures, and even the waysides, will afford you constant subjects for botanical observations. To the hardier sex, who can climb mountains, and penetrate marshes, many strange and interesting plants will present themselves, which cannot be found except in their peculiar situations, of these you must be content to obtain specimens, without seeing them in their native wilds. You will, no doubt, easily obtain such specimens, for there is, usually, among the cultivators of natural science, a generosity in affording assistance, and imparting to others the treasures which nature lavishes upon those who have a taste to enjoy them.

Method of preserving plants, and of preparing an herbarium-Botanical ar sions